Question:
If the distance between the foci of a hyperbola is 16 and its eccentricity is √2, then obtain the equation of the hyperbola.
Solution:
We know that equation of Hyperbola
$=\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1$
Also we have foci $=(\pm a e, 0)$
Given distance between foci is $2 \mathrm{ae}=16$
$e=\sqrt{2}$
$2 \times a \times \sqrt{2}=16$
$a=\frac{16}{2 \times \sqrt{2}}=\frac{8}{\sqrt{2}}=4 \sqrt{2}$
$\because b^{2}=a^{2}\left(e^{2}-1\right)$
$\mathrm{b}^{2}=(4 \sqrt{2})^{2}\left((\sqrt{2})^{2}-1\right)$
$=32(2-1)=32$
$\therefore$ Equation is $\frac{x^{2}}{32}-\frac{y^{2}}{32}=1$